Mr Obama said a decision would be announced within "several weeks"
President Barack Obama says he is "very close" to deciding whether to send more troops to Afghanistan and will announce his decision within "several weeks".
Mr Obama also told CNN in China his new strategy would emphasise an "endgame".
The top US military commander in Afghanistan, Gen Stanley McChrystal, wants at least 40,000 more US troops.
Meanwhile, US Secretary of State Hillary Clinton has arrived in Kabul to attend the inauguration of President Hamid Karzai after a fraud-marred poll.
Her visit is a clear sign that the US and its Nato allies have no choice but to work with Mr Karzai and he knows it, the BBC's State Department correspondent Kim Ghattas says.
Kim Ghattas, BBC News, Kabul
President Karzai will see Hillary Clinton's presence here as a ringing endorsement of his second term as leader.
But for Washington it is a qualified endorsement.
A US official travelling with the secretary of state said the electoral process in Afghanistan had produced this result and Washington had to deal with the facts on the ground.
But he also said Mrs Clinton would make clear to the Afghan president that the US and its allies expect him to do better in the coming years.
She adds that both Mr Obama and Mrs Clinton have made very public statements about the need to fight corruption.
Mrs Clinton has also warned civilian aid will not continue to flow to Afghanistan unless these issues are addressed.
She will make those points when she has dinner with Mr Karzai on Wednesday evening before his inauguration, our correspondent says.
Mr Obama said he did not want his successor as president to inherit the Afghan conflict, adding that a "multi-year occupation" would not serve US interests.
The US president made his comments during his trip to Asia, in interviews with NBC News, CNN and CBS News.
He pledged to make clear to Americans the reasoning behind his new strategy and its costs.
"The American people will have a lot of clarity about what we're doing, how we're going to succeed, how much this thing is going to cost, what kind of burden does this place on our young men and women in uniform and, most importantly, what's the end game on this thing," he said.
In the wake of the political upheaval that surrounded President Karzai's disputed re-election, Mr Obama also expressed concerns about the Afghan government's ability to be an "effective partner".
"I'm less concerned about any individual than I am with a government as a whole that is having difficulty providing basic services to its people in a way that confers legitimacy on them," Mr Obama said.
"We also have to make sure that we've got an effective partner in Afghanistan. And that's something that we are examining very closely and presenting some very clear benchmarks for the Afghan government."
An ABC News/Washington Post poll suggests 44% of US adults believe the Afghan war is worth fighting, the lowest proportion since polls began in 2007.
The US currently has about 68,000 troops in Afghanistan, contributing to a coalition force of more than 100,000.